1. The process of forming metal into sheets by passing it between rolls
   "The steel underwent flatting to create thin sheets for construction";
   - flattening

1. [Austral, NZ] Live in or share an apartment
   "They've been flatting together since university"
    
2. (music) lower a note's pitch by a semitone
   "The conductor asked the violinists to flat the B in measure 16"

Derived forms: flattings

Encyclopedia: Flatting